U.S. patent application number 12/311724 was filed with the patent office on 2010-02-04 for solution for treatment of resist substrate after development processing and method for treatment of resist substrate using the same.
Invention is credited to Masakazu Kobayashi, Go Noya, Ryuta Shimazaki.
Application Number | 20100028817 12/311724 |
Document ID | / |
Family ID | 39313951 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100028817 |
Kind Code |
A1 |
Noya; Go ; et al. |
February 4, 2010 |
Solution for treatment of resist substrate after development
processing and method for treatment of resist substrate using the
same
Abstract
The present invention provides a resist substrate-treating
solution for improving defects on a developed pattern surface, and
also provides a resist substrate treatment method employing the
treating solution. The resist substrate-treating solution comprises
a solvent and a nitrogen-containing or oxygen-containing
water-soluble polymer such as a polyamine, a polyol or a polyether.
In the treatment method, a developed resist pattern is treated with
the resist substrate-treating solution and then washed with pure
water.
Inventors: |
Noya; Go; (Shizuoka, JP)
; Shimazaki; Ryuta; (Shizuoka, JP) ; Kobayashi;
Masakazu; (Shizuoka, JP) |
Correspondence
Address: |
AZ ELECTRONIC MATERIALS USA CORP.;ATTENTION: INDUSTRIAL PROPERTY DEPT.
70 MEISTER AVENUE
SOMERVILLE
NJ
08876
US
|
Family ID: |
39313951 |
Appl. No.: |
12/311724 |
Filed: |
October 12, 2007 |
PCT Filed: |
October 12, 2007 |
PCT NO: |
PCT/JP2007/069978 |
371 Date: |
April 9, 2009 |
Current U.S.
Class: |
430/331 ;
430/432 |
Current CPC
Class: |
G03F 7/40 20130101 |
Class at
Publication: |
430/331 ;
430/432 |
International
Class: |
G03F 7/20 20060101
G03F007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2006 |
JP |
2006-285262 |
Claims
1. A developed resist substrate-treating solution, comprising a
solvent and a nitrogen-containing water-soluble polymer or an
oxygen-containing water-soluble polymer.
2. The developed resist substrate-treating solution according to
claim 1, wherein said nitrogen-containing water-soluble polymer is
an amino group-containing water-soluble polymer.
3. The developed resist substrate-treating solution according to
claim 2, wherein the amino group contained in said amino
group-containing water-soluble polymer is a primary amino
group.
4. The developed resist substrate-treating solution according to
claim 1, wherein said oxygen-containing water-soluble polymer is a
polyol or a polyether.
5. The developed resist substrate-treating solution according to
claim 1, wherein said nitrogen-containing water-soluble polymer or
said oxygen-containing water-soluble polymer is contained in a
concentration of 0.01 to 10% based on the total weight of the
developed resist substrate-treating solution.
6. A resist substrate treatment method, wherein a developed resist
pattern is treated with a resist substrate-treating solution
comprising a solvent and a nitrogen-containing water-soluble
polymer or an oxygen-containing water-soluble polymer, and is then
washed with pure water.
7. The resist substrate treatment method according to claim 6,
wherein the time for which said resist pattern is treated with said
resist substrate-treating solution is in the range of 1 to 300
seconds.
8. The resist substrate treatment method according to claim 6,
wherein washing with pure water is also carried out immediately
before the treatment with said resist substrate-treating
solution.
9. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer has
the structure (1) ##STR00005## where L.sup.1 and L.sup.2 are
independently a divalent linking group, R.sup.1 and R.sup.2 are
independently hydrogen or C.sub.1-C.sub.20 hydrocarbon, and p is
the degree of polymerization.
10. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer has
the structure (1) ##STR00006## where L.sup.1 and L.sup.2 are
independently a divalent linking group, R.sup.1 and R.sup.2 are
independently hydrogen or C.sub.1-C.sub.20 hydrocarbon, and p is
the degree of polymerization, and further where R.sup.1 and R.sup.2
may be combined to form a ring, or R.sup.1 or R.sup.2 may be
combined with carbon atoms in L.sup.1 or L.sup.2, respectively, to
form a ring.
11. The developed resist substrate-treating solution according to
claim 9, wherein L.sup.1, L.sup.2, R.sup.1 and R.sup.2
independently comprise a substituent group selected from hydroxyl,
carboxyl, amino, carbonyl and ether group.
12. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer is
polyallylamine.
13. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer is
poly-N-methylallylamine.
14. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer is
poly-N,N'-dimethyl-allylamine.
15. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer is
poly(N-methyl-3,5-piperidinediylmethylene).
16. The developed resist substrate-treating solution according to
claim 1, wherein the nitrogen-containing water-soluble polymer
comprises a unit selected from, ##STR00007##
17. The developed resist substrate-treating solution according to
claim 1, where the oxygen-containing water-soluble polymer is
preferably a polyol represented by the following formula (II) or a
polyether represented by the following formula (III), ##STR00008##
where, L.sup.3 to L.sup.5 are independently a divalent linking
group selected from single bond or divalent functional group,
R.sup.3 is selected from hydrogen, an alkyl group, an acetyl group,
a benzyl group and an acetal group, and q and r are numbers
indicating degree of polymerization.
18. The developed resist substrate-treating solution according to
claim 17, wherein L.sup.3, L.sup.5, and R.sup.3 independently
comprise a substituent group selected from hydroxyl, carboxyl,
amino, carbonyl and ether group.
19. The developed resist substrate-treating solution according to
claim 1, where the oxygen-containing water-soluble polymer is
##STR00009## Where R' is a carboxyl group.
Description
TECHNICAL FIELD
[0001] The present invention relates to a resist substrate-treating
solution. In detail, this invention relates to a resist
substrate-treating solution advantageously used in a developing
process of a photosensitive resin composition employed for
manufacture of semiconductor devices, flat panel displays (FPDs)
such as liquid crystal display elements, charge-coupled devices
(CCDs), color filters, magnetic heads and the like; and the
invention also relates to a developed resist substrate treatment
method using the treating solution.
BACKGROUND ART
[0002] In extensive fields including the manufacture of
semiconductor integrated circuits such as LSIs, the preparation of
FPD screens, and the production of circuit boards for color
filters, thermal heads and the like, photolithography has hitherto
been used for formation of fine elements or for microfabrication.
In the photolithography, a positive- or negative-working
photosensitive resin composition is used for resist pattern
formation. As the positive-working photoresist, a photosensitive
resin composition comprising an alkali-soluble resin and a
photosensitive substance of quinonediazide compound, for example,
is widely used.
[0003] Meanwhile, in recent years in manufacturing fine electronic
devices, increased integration density and highly accelerated
processing speed in LSIs have led to design rules requiring
quarter-micron- or finer-scale fabrication rather than
half-micron-scale fabrication, which the design rules formerly
required. Since conventional light for exposure such as visible
light or near UV light (wavelength: 400 to 300 nm) cannot fully
cope with the design rules requiring finer fabrication, it is
necessary to use radiation of shorter wavelength such as far UV
light emitted from a KrF excimer laser (248 nm), an ArF excimer
laser (193 nm) or the like, an X-ray or an electron beam.
Accordingly, lithographic processes using the radiation of shorter
wavelength have been proposed and gradually getting used in
practice. To cope with the design rules requiring finer
fabrication, the photoresist used in microfabrication must be a
photosensitive resin composition capable of giving a pattern of
high resolution. Further, it is also desired that the
photosensitive resin composition be improved not only in resolution
but also in sensitivity and in accuracy on shape and dimension of
the pattern. In view of this, as a radiation-sensitive resin
composition having sensitivity to the radiation of short wavelength
and giving a pattern of high resolution, a "chemically amplified
photosensitive resin composition" has been proposed. The chemically
amplified photosensitive resin composition comprises a compound
that generates an acid when exposed to radiation, and hence when
the radiation is applied, the compound generates an acid and the
acid serves as a catalyst in image-formation to improve
sensitivity. Since the chemically amplified photosensitive resin
composition is thus advantageous, it has been getting popularly
used in place of conventional photosensitive resin
compositions.
[0004] However, in accordance with increasing the fineness in
fabrication as described above, problems such as foreign substances
remaining on the substrate surface, pattern collapse and pattern
roughness have been getting apparent. To cope with those problems,
various methods have been studied. For example, it is studied to
improve resist compositions. Further, it is also studied to develop
a technology for improving the defects on the pattern surface (see,
Patent documents 1 and 2).
[0005] [Patent document 1] Japanese Patent Laid-Open No.
2004-78217
[0006] [Patent document 2] Japanese Patent Laid-Open No.
2004-184648
DISCLOSURE OF INVENTION
Problem to be Solved by the Invention
[0007] It is an object of the present invention to provide a resist
substrate-treating solution for improving defects (foreign
substances redeposited) on the surface of the developed pattern.
Further, it is another object of the present invention to provide a
resist substrate treatment method using that treating solution.
Means for Solving Problem
[0008] The present invention resides in a developed resist
substrate-treating solution, comprising a solvent and a
nitrogen-containing water-soluble polymer or an oxygen-containing
water-soluble polymer.
[0009] The present invention also resides in a resist substrate
treatment method, wherein a developed resist pattern is treated
with a resist substrate-treating solution comprising a solvent and
a nitrogen-containing water-soluble polymer or an oxygen-containing
water-soluble polymer, and is then washed with pure water.
EFFECT OF THE INVENTION
[0010] The present invention makes it possible, without seriously
increasing the production cost or impairing the production
efficiency, to form a developed pattern having few defects caused
by resist fragments redeposited on the remaining resist surface or
on the substance surface where the resist is removed by
development. In a production process according to the present
invention, it is unnecessary to introduce a new apparatus and it is
possible to employ relatively inexpensive materials, and hence a
pattern having excellent surface condition can be produced without
increasing the production cost.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] The pattern formation method according to the present
invention is described below in detail.
[0012] In the pattern formation method of the invention, a resist
pattern after development is treated with a resist
substrate-treating solution. There is no particular restriction on
the process by which a resist pattern is developed to obtain the
pattern to be treated, and hence any process can be used.
Accordingly, the lithographic process for preparing the pattern to
be treated can be carried out in any known manner of forming a
resist pattern from a conventional positive- or negative-working
photosensitive resin composition. Below described is a typical
process for forming a pattern to be treated with the resist
substrate-treating solution of the present invention.
[0013] First, a photosensitive resin composition is coated on a
surface, which can be pretreated, if necessary, of a substrate,
such as a silicon substrate or a glass substrate, according to a
known coating method such as spin-coating method, to form a
photosensitive resin composition layer. Prior to the coating of the
photosensitive resin composition, an antireflection film can be
beforehand formed by coating under or above the resist. The
antireflection film can improve the section shape and the exposure
margin.
[0014] Any known photosensitive resin composition can be used in
the pattern formation method of the present invention.
Representative examples of the compositions usable in the present
invention include: a composition comprising a quinonediazide type
photosensitive substance and an alkali-soluble resin, a chemically
amplified photosensitive resin composition (which are
positive-working compositions); a composition comprising a
photosensitive functional group-containing polymer such as
polyvinyl cinnamate, a composition comprising an azide compound
such as an aromatic azide compound or a bisazide compound with a
cyclized rubber, a composition comprising a diazo resin, a
photo-polymerizable composition comprising an
addition-polymerizable unsaturated compound, and a chemically
amplified negative-working photosensitive resin composition (which
are negative-working compositions).
[0015] Examples of the quinonediazide type photo-sensitive
substance used in the positive-working composition comprising a
quinonediazide type photosensitive substance and an alkali-soluble
resin include: 1,2-benzoquinonediazide-4-sulfonic acid,
1,2-naphtho-quinonediazide-4-sulfonic acid,
1,2-naphthoquinone-diazide-5-sulfonic acid, and sulfonic esters or
amides thereof. Examples of the alkali-soluble resin include:
novolak resin, polyvinyl phenol, polyvinyl alcohol, and copolymers
of acrylic acid or methacrylic acid. The novolak resin is
preferably prepared from one or more phenols such as phenol,
o-cresol, m-cresol, p-cresol and xylenol in combination with one or
more aldehydes such as formaldehyde and paraformaldehyde.
[0016] Either positive- or negative-working chemically amplified
photosensitive resin composition can be used in the pattern
formation method of the present invention. The chemically amplified
resist generates an acid when exposed to radiation, and the acid
serves as a catalyst to promote chemical reaction by which
solubility to a developer is changed within the areas irradiated
with the radiation to form a pattern. For example, the chemically
amplified photosensitive resin composition comprises an
acid-generating compound, which generates an acid when exposed to
radiation, and an acid-sensitive functional group-containing resin,
which decomposes in the presence of acid to form an alkali-soluble
group such as phenolic hydroxyl or carboxyl group. The composition
may comprise an alkali-soluble resin, a crosslinking agent and an
acid-generating compound.
[0017] The photosensitive resin composition layer formed on the
substrate is prebaked, for example, on a hot plate to remove
solvent contained in the composition, to form a photoresist film.
The prebaking temperature depends upon the solvent and the
photosensitive resin composition, but is normally 20 to 200.degree.
C., preferably 50 to 150.degree. C.
[0018] The photoresist film is then subjected to exposure through a
mask, if necessary, by means of known exposure apparatus such as a
high-pressure mercury lamp, a metal halide lamp, an ultra-high
pressure mercury lamp, a KrF excimer laser, an ArF excimer laser, a
soft X-ray irradiation system, and an electron beam lithography
system.
[0019] After the exposure, baking treatment may be carried out, if
necessary, and then development such as paddle development is
carried out to form a resist pattern. The resist is normally
developed with an alkali developer. Examples of the alkali
developer include an aqueous solution of sodium hydroxide or
tetramethylammonium hydroxide (TMAH). After the development, the
resist pattern is rinsed (washed) with a rinse solution,
preferably, pure water. The thus-formed resist pattern is employed
as a resist for etching, plating, ion diffusion or dyeing, and
then, if necessary, peeled away.
[0020] The resist substrate treatment method according to the
present invention can be applied to a resist pattern of any pattern
size. However, the method according to the present invention is
remarkably effective in improvement when the method is applied to
produce a fine resist pattern required to have delicate surface
character and precise dimension. Accordingly, the method of the
present invention is preferably combined with a lithographic
process capable of giving a fine resist pattern, such as, a
lithographic process comprising exposure at a wavelength of 250 nm
or shorter with a light source of a KrF excimer laser, an ArF
excimer laser, an X-ray irradiation system or an electron beam
lithography system. Further, the lithographic process preferably
produces a resist pattern having a pattern dimension in which a
line width of the line-and-space pattern is not more than 300 nm,
preferably not more than 200 nm or in which a hole diameter of the
contact hole pattern is not more than 300 nm, preferably not more
than 200 nm.
[0021] The thickness of the resist pattern is properly determined
according to the aimed use, but is in the range of generally 0.1 to
5 .mu.m, preferably 0.1 to 2.5 .mu.m, more preferably 0.2 to 1.5
.mu.m.
[0022] In the resist substrate treatment method of the present
invention, a resist pattern after subjected to development is
treated with a resist substrate-treating solution containing water
and a nitrogen-containing water-soluble polymer or an
oxygen-containing water-soluble polymer. As the nitrogen-containing
or oxygen-containing water-soluble polymer, any polymer can be used
as long as it contains a nitrogen atom or an oxygen atom and is
soluble in water.
[0023] The nitrogen-containing water-soluble polymer contains a
nitrogen atom in the form of, for example, an amino group, a
pyrazole group or an amide group. Preferred is a water-soluble
polymer containing an amino group. There is no particular
restriction on the number of the nitrogen atoms contained in the
polymer. However, in order to enhance the effect on reducing the
pattern size, the number of nitrogen atoms is preferably 5 to 5000,
more preferably 5 to 2000 per molecule of the polymer.
[0024] The nitrogen-containing water-soluble polymer is preferably
a polyamine represented by the following formula (I):
##STR00001##
in which L.sup.1 and L.sup.2 are divalent linking groups such as
single bonds or divalent functional groups. There is no particular
restriction on the number of carbon atoms contained in L.sup.1 and
L.sup.2, but each contains preferably 0 to 20 carbon atoms, more
preferably 0 to 5 carbon atoms. The groups L.sup.1 and L.sup.2 are
not particularly restricted, but they are generally hydrocarbon
groups, preferably alkylene groups or arylene groups, more
preferably alkylene groups. In the formula, R.sup.1 and R.sup.2 may
be any functional groups. There is no particular restriction on the
number of carbon atoms contained in R.sup.1 and R.sup.2, but they
are generally hydrogen atoms or hydrocarbon groups and hence each
contains preferably 0 to 20 carbon atoms, more preferably 0 to 5
carbon atoms. The groups R.sup.1 and R.sup.2 are not particularly
restricted, but they are generally hydrocarbon groups, preferably
alkyl groups or aryl groups, more preferably alkyl groups. The
groups R.sup.1 and R.sup.2 may be combined to form a ring, or
otherwise R.sup.1 or R.sup.2 may be combined with carbon atoms in
L.sup.1 or L.sup.2, respectively, to form a ring. In the above
formula, p is a number indicating polymerization degree. If
necessary, each of the groups L.sup.1, L.sup.2, R.sup.1 and R.sup.2
may have a substituent group such as hydroxyl, a carboxyl group, an
amino group, a carbonyl group or an ether group. In one molecule of
the polymer, two or more different groups may serve as each of
L.sup.1, L.sup.2, R.sup.1 and R.sup.2. Further, in the case where
the groups L.sup.1, L.sup.2, R.sup.1 and R.sup.2 contain carbon
atoms, the number of the carbon atoms is selected within such a
range that the polymer can be dissolved in water at a predetermined
concentration. For example, L.sup.1 and L.sup.2 are preferably an
alkylene group and methylene, respectively. Examples of the
polyamine include polyallylamine, poly-N-methylallylamine,
poly-N,N'-dimethylallylamine, and
poly(N-methyl-3,5-piperidinediylmethylene). The polymerization
degrees of those polymers are not particularly restricted, and can
be desirably determined according to various conditions such as the
monomer structure, concentration of the resist substrate-treating
solution and the resist compound. However, the number of p in
polyallylamine is generally 5 to 500, preferably 10 to 400. The
number of p in poly-N,N'-dimethyl-allylamine is generally 5 to 50,
preferably 5 to 30, and that in
poly(N-methyl-3,5-piperidinediylmethylene) is generally 5 to 50,
preferably 10 to 30. Concrete examples of structures and
polymerization degrees of the preferred polymers are shown below.
The shown polymers are commercially available from, for example,
Nitto Boseki Co., Ltd.
##STR00002##
[0025] If both R.sup.1 and R.sup.2 in the formula (I) are hydrogen
atoms, namely, if the nitrogen atom in the formula (I) forms a
primary amino group, the effect of the present invention is
enhanced. Accordingly, the polymer having that structure, for
example, the polymer of the above (Ia) or (Ib) is particularly
preferred.
[0026] The oxygen-containing water-soluble polymer contains an
oxygen atom in the form of, for example, hydroxyl, an ether group,
a carboxyl group, a carbonyl group or an amide group. Preferred is
a water-soluble polymer containing hydroxyl or an ether group.
There is no particular restriction on the number of the oxygen
atoms contained in the polymer. However, in order to enhance the
effect on reducing the pattern size, the number of oxygen atoms is
preferably 5 to 3000, more preferably 5 to 1000 per molecule of the
polymer.
[0027] The oxygen-containing water-soluble polymer is preferably a
polyol represented by the following formula (II) or a polyether
represented by the following formula (III):
##STR00003##
[0028] In the above formulas, L.sup.3 to L.sup.5 are divalent
linking groups such as single bonds or divalent functional groups.
There is no particular restriction on the number of carbon atoms
contained in the linking groups, but each contains preferably 0 to
20 carbon atoms, more preferably 0 to 5 carbon atoms. The linking
groups are not particularly restricted, but they are generally
single bonds or hydrocarbon groups. Among the hydrocarbon groups,
alkylene groups or arylene groups are preferred and alkylene groups
are more preferred. In the formula (II), R.sup.3 may be any
functional group but is preferably hydrogen, an alkyl group or a
protecting group such as acetyl, benzyl or an acetal group. There
is no particular restriction on the number of carbon atoms
contained in R.sup.3, which is generally hydrogen or an alkyl
group. The number of carbon atoms contained in R.sup.3 is
preferably 0 to 20, more preferably 0 to 5. In the above formulas,
q and r are numbers indicating polymerization degrees. If
necessary, each of the groups L.sup.3 to L.sup.5 and R.sup.3 may
have a substituent group such as hydroxyl, a carboxyl group, an
amino group, a carbonyl group or an ether group. In one molecule of
the polymer, two or more different groups may serve as each of
L.sup.3 to L.sup.5 and R.sup.3. Further, in the case where the
groups L.sup.3 to L.sup.5 and R.sup.3 contain carbon atoms, the
number of the carbon atoms is selected within such a range that the
polymer can be dissolved in water at a predetermined concentration.
The oxygen-containing water-soluble polymer is, for example, a
compound represented by the following formula.
##STR00004##
in which R' is a carboxyl group and the molecular weight is approx.
24000. The polymer of the formula (IIa) is commercially available
(e.g., PV-205 [trade mark], manufactured by Kuraray Co., Ltd.).
Further, polyols, polyacrylic acid and polymethacrylic acid are
also usable as the oxygen-containing water-soluble polymers. These
water-soluble polymers are commercially available (e.g., JURYMER
AC-10SL [trade mark], manufactured by Nihon Junyaku Co., Ltd.; and
POVAL [trade mark], manufactured by Kuraray Co., Ltd.).
[0029] According to the requirement, it is possible to use the
nitrogen-containing or oxygen-containing water-soluble polymer
having a desired molecular weight. The molecular weight of the
polymer is in the rage of generally 500 to 200000, preferably 1000
to 100000. However, since the proper molecular weight depends upon
the main chain structure and the functional groups, it is often
possible to use the polymer having a molecular weight out of the
above range.
[0030] Two or more polymers can be used in combination, if
necessary.
[0031] The resist substrate-treating solution according to the
present invention comprises a solvent as well as the aforementioned
nitrogen-containing or oxygen-containing water-soluble polymer.
There is no particular restriction on the solvent, and any solvent
can be used. However, in consideration of affinity with the
developer and the rinse solution, water is preferably used.
However, for improving wettability, a small amount of organic
solvent can be added as a cosolvent. Examples of the cosolvent
include alcohols such as methanol and ethanol, ketones such as
acetone and methyl ethyl ketone, and esters such as ethyl acetate.
If necessary, other auxiliary components can be incorporated. For
example, acidic or basic substances and surfactants can be added
unless they impair the effect of the present invention.
[0032] There is no particular restriction on the concentration of
the nitrogen-containing or oxygen-containing water-soluble polymer
dissolved in the treating solution, but it is preferred to control
the concentration according to what the pattern is used for and how
the pattern is used. Generally, the treating solution containing
the polymer in a high concentration is apt to shorten the time to
complete the treatment, and gives large effect on improving the
foreign substances redeposited on the pattern surface. On the other
hand, if the treating solution contains the polymer in a low
concentration, it takes a short time to complete rinsing with pure
water after the treatment. Further, what kind of the polymer is
most preferred and how much amount is most preferred are dependent
upon the photo-sensitive resin composition and other conditions.
Accordingly, the concentration is preferably so determined that the
required characteristics can be obtained in good balance. The
optimum concentration of the nitrogen-containing or
oxygen-containing water-soluble polymer is thus not fixed, but is
generally in the range of 0.01 to 10%, preferably 0.1 to 5%, more
preferably 0.1 to 2% based on the total weight of the developed
resist substrate-treating solution.
[0033] The treatment of resist pattern by use of the resist
substrate-treating solution can be performed, for example, by
immersing the resist substrate in the treating solution or by
subjecting the resist substrate to dip-coating or paddle-coating
with the treating solution. The time for which the resist substrate
is treated with the treating solution, namely, the treatment time
is not particularly limited. However, to enhance the effect on
improving the foreign substances redeposited on the pattern
surface, the treatment time is preferably not less than 1 second,
more preferably not less than 10 seconds. The upper limit of the
treatment time is not particularly limited, but the treatment time
is preferably not more than 300 seconds in view of the production
efficiency.
[0034] There is also no particular restriction on the temperature
of the treating solution. However, in view of the effect on
improving the foreign substances redeposited on the pattern
surface, the temperature is generally in the range of 5 to
50.degree. C., preferably 20 to 30.degree. C.
[0035] Generally in the resist substrate after subjected to
development, fragments of the resist removed by the development are
often redeposited as foreign substances on the surface where the
resist still remains or on the bared substrate surface where the
resist is removed by the development. According to the resist
substrate treatment method of the present invention, the
redeposited resist fragments can be removed to obtain the surface
having few defects. The mechanism of this effect is yet to be
revealed clearly. However, it is presumed that the nitrogen atoms
or the oxygen atoms in the water-soluble polymer contained in the
resist-treating solution adsorb the redeposited resist fragments by
use of their unpaired electrons or by hydrogen bonding, so as to
remove the resist fragments redeposited on the remaining resist
surface or on the bared substrate surface.
[0036] In the resist substrate treatment method according to the
present invention, the resist substrate is rinsed with pure water,
namely, is subjected to rinse step, after treated with the
aforementioned treating solution. This rinse step is carried out
for the purpose of washing out the resist substrate-treating
solution. Particularly in the case where the treating solution has
a high concentration, the rinsing with pure water is inevitably
carried out after the treatment with the treating solution so that
the resist pattern may not undergo troubles in the subsequent
steps, for example, so that the treating solution remaining on the
resist surface may not cause problems in the etching step.
[0037] Further, in the resist substrate treatment method according
to the present invention, it is preferred that the resist substrate
after subjected to development be also rinsed with pure water
before treated with the treating solution containing the polymer of
the present invention. The rinse step before the treatment with the
treating solution is carried out for the purpose of washing out a
developer remaining on the resist pattern. In order to prevent the
developer from contaminating the treating solution and to treat the
resist substrate with a minimum amount of the treating solution,
the resist substrate after development is preferably rinsed with
pure water before treated with the treating solution.
[0038] The rinsing with pure water can be carried out in a desired
manner. For example, the resist substrate is immersed in the rinse
solution, or otherwise the rinse solution is dropped or sprayed
onto the substrate surface while the substrate is being
rotating.
[0039] In the present invention, the resist pattern after
development is treated with the aforementioned resist
substrate-treating solution. After the development or after the
rinsing with pure water, the resist pattern is normally not dried
and immediately treated with the treating solution. However, if
necessary, before treated with the treating solution, the resist
pattern can be dried immediately after the development or after the
rinsing procedure subsequent to the development. Even so, the
effect of the invention can be obtained.
[0040] The resist pattern whose surface condition is thus improved
by the resist substrate treatment method of the present invention
is then further processed according to the aimed use. The resist
substrate treatment method of the present invention by no means
restricts the subsequent steps, and hence the resist pattern can be
processed in known manners.
[0041] The pattern formed by the method of the present invention
can be employed for manufacture of flat panel displays (FPDs) such
as liquid crystal displays, charge-coupled devices (CCDs), color
filters, magnetic heads and the like, in the same manner as the
pattern formed by the conventional method is employed for.
[0042] The present invention is further explained by use of the
following Examples, but they by no means restrict the embodiments
of the present invention.
Comparative Example 1
[0043] An anti-reflection film-forming composition (AZ KrF-17B
[trade mark], manufactured by AZ Electronic Materials (Japan) K.K.)
was spin-coated on an 8-inch silicon wafer by means of a spin
coater (manufactured by Tokyo Electron Limited), and then baked on
a hot-pate at 180.degree. C. for 60 seconds to obtain a 800
.ANG.-thick film. The thickness was measured by a thickness monitor
(manufactured by Prometrix). On the thus-obtained anti-reflection
film, a 248 nm-exposure type chemically amplified photoresist
containing a polymer of polystyrene skeleton (AZ DX 6850P [trade
mark], manufactured by AZ Electronic Materials (Japan) K.K.) was
spin-coated and then baked on a hot-pate at 100.degree. C. for 90
seconds to obtain a 0.68 .mu.m-thick resist film. The obtained
resist film was then subjected to exposure by means of a reduced
projection exposure apparatus (FPA-3000EX5 [trade mark],
manufactured by Canon Inc.) with Quadropole at 248 nm. Thereafter,
the resist substrate was baked on a hot-pate at 110.degree. C. for
60 seconds, and then paddle development was carried out with 2.38
wt. % aqueous solution of tetramethylammonium hydroxide (developer
AZ 300MIF [trade mark], manufactured by AZ Electronic Materials
(Japan) K.K.) at 23.degree. C. for 1 minute. Successively, after
rinsed with pure water, the resist substrate was spin-dried to
obtain a short line pattern of 250 nm.
Comparative Example 2
[0044] After developed in the same manner as in Comparative Example
1,
[0045] (a) the resist substrate was not rinsed with pure water and
immediately treated with the resist substrate-treating solution for
20 seconds, or
[0046] (b) the resist substrate was not rinsed with pure water and
immediately treated with the resist substrate-treating solution for
20 seconds, and then rinsed with pure water for 15 seconds, or
otherwise
[0047] (c) the resist substrate was rinsed with pure water and
treated with the resist substrate-treating solution for 15 seconds,
and then rinsed again with pure water for 15 seconds. The resist
substrate-treating solution used in each treatment contained
triethanolamine in various concentrations shown in Table 1.
EXAMPLES
[0048] The procedure of Comparative Example 2 was repeated except
for using resist substrate-treating solutions containing the
polymers shown in Table 1 in various concentrations shown in Table
1.
[0049] The resist patterns obtained above were observed by means of
a surface defects inspector (KLA-2115 [trade mark], manufactured by
KLA-Tencor Co.), to evaluate the foreign substances redeposited on
the pattern surface. The results were as set forth in Table 1.
[0050] [Table 1]
TABLE-US-00001 TABLE 1 Evaluation of redeposited foreign substances
according to concentration of resist-treating solution
Concentration of resist-treating solution Polymer Procedures 0%
0.01% 0.1% 1% 2% 5% Triethanolamine develop - treat >10000
>10000 >10000 >10000 >10000 >10000 develop - treat -
rinse >10000 >10000 >10000 >10000 >10000 develop -
rinse - treat - rinse >10000 >10000 >10000 >10000
>10000 (Ia) develop - treat >10000 >10000 >10000
>10000 >10000 >10000 develop - treat - rinse 0 0 0 0 0
develop - rinse - treat - rinse 0 0 0 0 0 (Ib) develop - treat
>10000 >10000 >10000 >10000 >10000 >10000 develop
- treat - rinse 0 0 0 0 0 develop - rinse - treat - rinse 0 0 0 0 0
(Ic) develop - treat >10000 >10000 >10000 >10000
>10000 >10000 develop - treat - rinse 952 883 56 48 38
develop - rinse - treat - rinse 513 435 23 56 20 (Id) develop -
treat >10000 >10000 >10000 >10000 >10000 >10000
develop - treat - rinse 943 760 189 85 65 develop - rinse - treat -
rinse 825 654 46 37 26 (IIa) develop - treat >10000 >10000
>10000 >10000 >10000 >10000 develop - treat - rinse
9035 634 13 8 6 develop - rinse - treat - rinse 5053 334 5 3 4
Remark) melt.: the resist surface was melted.
* * * * *